Moldable, needle-punched automotive carpet

ABSTRACT

An improved moldable, needle-punched automotive carpet of improved wear is disclosed by the invention process of combining a critical proportion of polypropylene and polyester fibers having optimal physical properties. A preferred embodiment of the invention additionally includes a binder fiber. The improved carpet comprises a blend of fibers with specific properties that, when used to manufacture the needle-punched auto carpet, produces a moldable carpet that exhibits improved wear, heretofore achieved only with more expensive tufted carpets.

FIELD OF THE INVENTION

The present invention relates to better performing carpets forautomotive flooring. In particular, the present invention relates toimproved durability in carpets for automotive flooring. Moreparticularly, the present invention relates to durable needle-punchedcarpets capable of being molded to conform to the shape of theautomotive floor.

PRIOR ART

Automotive carpeting is made primarily by two methods. In a commonmethod, solution-dyed extruded polyester fiber is “needle-punched.” Inanother common method, a colored extruded bulk continuous filament (BCF)nylon fiber is more thickly “tufted” on a fabric backing material.Tufted automotive carpets typically are more expensive thanneedle-punched. Alternatively, tufted auto carpets may be made withuncolored nylon and later dyed.

a. Tufted Carpets

The use of molded carpet modules for carpeting motor vehicle interiorsis an old and well-established practice. U.S. Pat. Nos. 5,474,829 and5,605,108 recite the teachings of U.S. Pat. Nos. 3,953,632 and4,579,764, which latter patents are concerned with backing materials andmolding features forming the modules. Also, recited are U.S. Pat. Nos.4,871,602 and 5,109,784, which patents are directed to floor mats foruse in automobiles that have strips in which more pile yarn is tuftedinto the backing fabric to form an area more resistant to wear.

The '829 and '108 patents themselves are directed, respectively, to avariable density motor vehicle carpet and a method of forming same. Themethod includes tufting in such a manner that selected areas have piletufts arranged at lower densities than the selected high density areas,with the areas of high density having a greater resistance to wear thatthe areas of low density.

U.S. Pat. No. 4,016,318 discloses a method of making a moldableautomobile mat formed of a tufted carpet having a stiff, heat-moldablethin layer urethane resin layer bonded to the back of the carpet tosecure the tufts to the carpet and having a thick layer of a flexible,cross-linked, thermoset, elastomeric urethane resin secured to the stiffthermoplastic urethane resin layer.

b. Needle-Punched Carpets

Needled textile fabrics are normally composed of synthetic organictextile fibers, such as polyester or polypropylene fibers, needledtogether into a consolidated mat. Such fabrics may also be made ofnatural organic fibers capable of being formed into a non-woven fabricof substantial properties by the more traditional process, such asfelting, and as such, are not usually needled to form a non-wovenfabric.

Thus, most needled fabrics, being composed generally of syntheticorganic fibers, find a variety of applications where relatively highphysical properties are required, e.g. high strengths, withsubstantially uniform physical properties in both the longitudinal andwidthwise direction, and particularly in those applications whereeconomics dictate the use of materials less expensive than tuftedfabrics or where the applications require more uniform thicknessdirection properties than tufted fabrics. Fabrics are generallyrestricted to synthetic organic fibers, but the application of usingpolypropylene fiber needled fabrics has been substantially limited whenhigher temperatures are involved. Thus, the normal polypropylene fiberneedled fabrics suffer from considerable disadvantages in these regards.(U.S. Pat. No. 5,547,731 teaches “Needled Carpet and a Process forProducing It.”)

The art has attempted to overcome these disadvantages by use of a numberof different approaches. Blends using polypropylene were used, butwithout significant improvement in wear performance.

The European and US car manufacturers have very different standards forthe wear performance of flooring carpets. In the US, until a few yearsago all the automotive flooring products were tufted and had to meet aperformance of from about 2,000 to about 3,000 cycles on the TaborAbrader test, requiring more expensive tufted carpeting. In Europe,however, the standard is about 300 cycles on the Tabor Abrader test,permitting use of less expensive needle-punched carpeting. The reasonfor this difference in performance standards is that in Europe mostmanufacturers sell their vehicles with separate additional floor mats.Because of the mats, they do not need their flooring to perform to ahigher standard. In the US, on the other hand, the big three automanufacturers sell most of their cars without separate floor mats;therefore, they needed a better performing base flooring product. In thelast few years, at least Ford and GM have specified one needle-punchedproduct for one of their vehicles. In both cases, they had to lowertheir standards for the Tabor Abrader test to about 1,000 cycles to“qualify” a needle-punched carpet product. Both companies have expressedtheir interest in a needle-punched product that would give them betterperformance. This desire to introduce a needle-punched product intotheir flooring systems, on a broader basis, comes from a drive to lowercosts, with minimum loss of quality.

Needle-punched carpets made of the polypropylene fiber alone typicallyperforms better than needle-punched carpets made solely of polyester inthe Tabor Abrader test. However, a needle-punched carpet formed ofpolypropylene fiber alone is not moldable; whereas a needle-punchedcarpet formed of polyester fiber alone is moldable. (All flooringsystems for US cars are molded.) So, there exists a need in the industryfor a less expensive, durable, moldable auto carpet.

SUMMARY OF THE INVENTION

By combining a critical proportion of polypropylene and polyesterfibers, a process was developed to produce an improved moldable,needle-punched automotive carpet. The improved carpet comprises a blendof fibers with specific properties that, when used to manufacture theneedle-punched auto carpet, exhibits improved the wear and produces amoldable carpet, heretofore achieved only with more expensive tuftedcarpets. In addition to the critical blend of specific fibers, it wasdiscovered that the addition of a binder fiber enhances the wearperformance of carpets made from this critical fiber blend. As anoptional last process step, it was further discovered that a uniquefinish material additionally improved the wear performance of carpetsmade from the blend of fibers disclosed herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Known needled-punched carpets typically have a backing of film or latex.After being needled, the tightly integrated fibers are impregnated witha binder, like latex or molten polyester or other like material. Thisway, the fibers in the top of the carpet are reinforced and anchoredfast, so they cannot be pulled out as the carpet is used.

In U.S. Pat. No. 4,389,443, a cut pile fabric is taught. The cut pilefabric includes a needled non-woven batt of staple fibers that has anintegral carrier member formed by fusing a face surface of the needledbatt. A texturized surface is formed on the batt using a texturizedneedle loom, which punches through the batt from the one surface (calledthe back surface) of the batt so that texturized loops project from thecarrier member. The non-texturized back surface of the batt typicallyhas a backing applied as by latexing, fusing, or the like, with thetexturized loops being tigered by a tigering roll to break, fracture orcut a high percentage of the loops. The tigered pile is typicallypolished by a polishing roll to remove the crimps in the fibers and toorient the fibers in a direction transverse to the plane of the battprior to being sheared in a shear. A dense, plush, lightweight cut pilefabric is produced having stability and strength. The patent examplesemployed polyethylene fibers only, and the resultant stable, strong pilefabric was not molded.

It is understood that the invention moldable, needle-punched automotivecarpet with improved wear performance may be prepared by methodsgenerally known in the art. The invention improvement lies in thematerials employed, as specified and claimed herein.

Needle-Punch Process

State-of-the-art computerized production lines for the manufacture ofneedle-punched carpets typically start with the provision of a rawmaterial resin in the form of pellets from rail hopper cars andtransferred, for storage until fed into the production line, in silos.

The first step in the production process is extrusion and spinning. (Inthe case of polyester, the resin material is crystallized and driedbefore extrusion.) The resin is usually blended uniformly, in moltenstate, with color pigments and other additives. The molten blend isextruded and flows under pressure through spinnerettes. (The denier andshape of the fiber is determined at this point.)

The next step involves drawing and annealing the fiber. During drawing,individual filaments are mellowed with heat, stretched, and annealed toachieve the elongation characteristics and strength required. In asubsequent step after drawing, the fiber is crimped to a “Z” shape forfiber cohesion, heat set, and cut to the desired length. Cut fibers arebaled and, if necessary, are blended in certain proportions with otherfibers appropriate for a specific fabric in production.

These bales of prepared fibers can then be opened and broken into clumpsof fiber in hoppers designed to achieve a uniform fiber dispersion. Theneedle-punch operation begins with a carding operation, where fibers inthe dispersion are combed by saw-toothed wire cylinders into a uniformweb in which the orientation of alignment of individual fibers isclosely controlled. Rollers then move the web of aligned fibers throughcross-lapping equipment that operates to build up layers of fiber websto achieve the desired weight and to improve uniformity of propertiesacross the width of the web. Finally, the process gets its name bypassing the layed-up (or cross-lapped) web through a needle loom whererepetitive penetration by barbed needles binds the web into a tightfabric by mechanical entanglement of the fibers. The finished fabricleaving the needle loom is then taken up on rolls.

The Materials

Polypropylene is a very versatile polymer. It serves double duty, bothas a plastic and as a fiber. As a fiber, polypropylene is used to makedurable carpeting, such as indoor-outdoor, as well as automobilecarpets. It works well for outdoor carpet because it is easy to makecolored polypropylene, and because polypropylene doesn't absorb water,like nylon does. These are also reasons it performs well for autocarpets. The polypropylene preferred in the present invention is roundand exhibits a denier of from 10 to 25, preferably 16-20, and mostpreferably 18. The preferred polypropylene also exhibits a tenacity offrom 2.2 to 6 g/denier, preferably from 3 to 5 g/denier, and mostpreferably 4 g/denier.

The polyester preferred for use in the present invention is anotherversatile fiber. It is used for needle-punched carpets, trunk liners,and auto headliners, among other uses. Preferably, the polyester is alsorecyclable. The polyester fiber of the invention is round and exhibitsD_(tex) value from 10 to 25, preferably 18±1.5, a tenacity value of2.5-4.6 g/denier, preferably 3.5±1.5 g/denier and an elongation at breakof 70%±35%.

The invention wear improvement in a moldable, needle-punched auto carpetis preferably achieved by inclusion of a binder fiber. The binder fibershould exhibit a relatively low softening temperature that may include apolycaprolactone, a polyethylene, and a polyester. The preferred binderfiber for inclusion in the invention is a polyester that is a meltactivated thermobonding fiber that exhibits a D_(tex) value from 2 to16, preferably 4±1.0, and an activation temperature range of 100-185°C., preferably 110-180° C.

The invention wear improvement in a moldable, needle-punched auto carpetis also preferably achieved by inclusion of a lubricant. The preferredlubricant for inclusion in the invention is a non-yellowing yarnlubricant is a homogenous blend of polymers and surfactants that isdispersible in cold and hot water, is nonionic or mildly amphoteric,exhibits a pH from 5.0-7.0 and has a density 6-10 lbs/gal, preferably7-8 lbs/gal, and most preferably 8.3 lbs/gal.

Fiber loss and wear criteria for acceptability in auto carpet flooringare primarily determined by passing established minimum standards.Specimens tested for fiber loss cannot exceed 10% weight loss. Specimenstested for wear must achieve a satisfactory rating after 1400 taber wearcycles, 600 cycles for fiber loss plus an additional 800 cycles forwear. The taber wear test involves exposing a carpet specimen torepetitive rotations of the taber abrader. To achieve a rating ofsatisfactory, there shall be no backing scrim visible for tufted carpetsand no complete holes for nonwoven carpets.

EXAMPLE 1

Fiber loss was measured in auto floor system samples of variouscompositions of polypropylene and/or polyester fibers. The followingdata show the least percent weight loss for the improved wear moldable,needle-punched carpet samples.

Data was collected from samples prepared as follows:

All samples tested were prepared in the manner of needle-punched carpetpreparation disclosed above. “A” designated samples were prepared of100% polyester with latex backing. “B” designated samples were preparedof 100% polypropylene with latex backing. “C” and “D” designated sampleswere prepared of 70:30 polyester/polypropylene with latex backing. “E”and “F” designated samples were prepared of 65% polyester, 28%polypropylene with 7% binder fiber with latex backing. “G” and “H”designated samples were prepared of 65% polyester, 28% polypropylenefused with 7% binder fiber. “J” through “M” designated samples wereprepared of 65% polyester, 28% polypropylene fused with 7% binder fiber.“N” and “P” designated samples were prepared of 100% polyester fiber,and represent the current auto carpet product being marketed to at leastone major U.S. auto manufacturer. “Q” through “T” designated sampleswere prepared of 18 denier 65% polyester, 28% polypropylene blends with7% binder fiber with latex backing.

For the purposes of these examples, the polypropylene fiber used wasstandard automotive grade fiber manufactured by Drake Extrusion Inc. Thepolyester fiber employed in the samples containing same was FOSSFIBRE®Solution Dyed PET, available from Foss Manufacturing Co., Inc. The fiberbinder employed in the samples was FOSSFIBRE® TYPE 410 PETG, from FossManufacturing Co., Inc. The lubricant employed in the samples forexamples was FLUFTONE® APS manufactured by Apollo Chemical Corporation.TABLE I Floor System Samples 1000 cycles 1400 cycles 2000 cycles 2500cycles A1 4.90% A2 4.71% A3 4.75% A4 4.75% B1 3.07% B2 2.96% B3 3.12% B43.09% C1 2.72% C2 2.50% D1 2.57% D2 2.83% E1 3.02% E2 2.77% F1 3.03% G12.92% G2 3.26% HI 3.44% H2 3.54% J1 2.02% J2 2.20% K1 2.38% K2 2.64% LI2.48% L2 2.32% M1 2.23% N1 3.72% N2 4.11% P1 3.59% P2 3.29% Q1 1.63% R11.63% SI 1.29% T1 1.95%

Comparisons between samples “A” and “B” show the reduced fiber lossusing polypropylene versus polyester fibers. Comparisons between samples“C” and “D” show only a minor increase in fiber loss at 1400 cycles(2.70% ave.) versus 1000 cycles (2.61% ave.). Similarly, comparisonsbetween latex-backed, fiber blended samples “E” and “F” show only aminor increase in fiber loss at 1400 cycles (3.03%) versus 1000 cycles(2.88%). At both 1000 cycles (3.09% ave.) and 1400 cycles (3.49% ave.),fused, fiber blended samples “G” and “H” experienced greater fiber lossthan same fiber based “E” and “F.” Yet, molded, fiber blended samples“J” through “M” showed significant reductions in fiber loss over earlierfiber-blended samples at 1000 cycles (2.11% ave.), 1400 cycles (2.51%ave.), 2000 cycles (2.4% ave.) and 2500 cycles (2.23%). Current productsamples (100% polyester) showed poor fiber loss performance at the lowercycle ranges (3.91% ave. at 1000 cycles and 3.44% ave. at 1400 cycles).Finally, by far the best fiber loss reductions were achieved by theinvention fiber blend samples at each cycle count tested.

Thus, Table I shows the improvement (i.e., reduction) in percent fiberloss in the disclosed invention wear improved carpet employing thedisclosed and claimed composition of fibers over carpet manufacturedemploying prior art materials.

EXAMPLE 2

The tabor abrader test (ASTM D3884-92), as discussed above, indicatingstandards for pass/fail determinations for floor carpeting wereconducted on samples of the same carpet compositions of Example 1. Thetabor abrader pass/fail determinations are shown in Table II below.TABLE II Sample Results A1 Fail A2 Fail A3 Fail A4 Fail B1 Fail B2 FailB3 Fail B4 Fail C1 Pass C2 Pass D1 Fail D2 Pass E1 Fail E2 Fail F1 FailG1 Pass G2 Pass HI Pass H2 Pass J1 Pass J2 Pass K1 Pass K2 Pass L1 PassL2 Pass M1 Fail N1 Pass N2 Pass P1 Fail P2 Fail Q1 Pass R1 Pass S1 PassT1 Pass

As might be expected, reduced wear generally corresponded with the fiberloss values as shown in Table I. Thus, improved wear reduction wasobserved with the invention fiber blend compositions than was observedwith the conventional carpet constructions.

It is to be understood that the present invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments, and of being practiced or carried out in variousways within the scope of the claims. Also it is to be understood thatthe phraseology and terminology employed herein is for the purpose ofdescription and not of limitation.

1. An integral textile composite fabric of non-woven, needled textilefibers comprising a blend of at least one polypropylene textile fiberand at least one polyester textile fiber of laid and needled textileorganic fibers.
 2. The composite fabric of claim 1 further comprisingthe addition of a binder fiber.
 3. The composite fabric of claim 2further comprising a yarn lubricant.
 4. The composite fabric of claim 1wherein the ratio of polyester to polypropylene is 60-80:40-20.
 5. Thecomposite fabric of claim 4 wherein the ratio of polyester topolypropylene is 70:30.
 6. The composite fabric of claim 2 wherein theratio of polyester to polypropylene to binder fiber is 75-55:20-35:5-10.7. The composite fabric of claim 6 wherein the ratio of polyester topolypropylene to binder fiber is 65:28:7.
 8. The composite fabric ofclaim 2 exhibiting a fabric loss less than 4.0 wt % after 1000 taborcycles.
 9. The composite fabric of claim 8 exhibiting a fabric loss lessthan 4.0 wt % after 1400 tabor cycles.
 10. The composite fabric of claim8 exhibiting a fabric loss less than 3.0 wt % after 1000 tabor cycles.11. The composite fabric of claim 10 exhibiting a fabric loss less than3.0 wt % after 1400 tabor cycles.
 12. The composite fabric of claim 10exhibiting a fabric loss less than 2.0 wt % after 1000 tabor cycles. 13.The composite fabric of claim 12 exhibiting a fabric loss less than 2.0wt % after 1400 tabor cycles.
 14. The composite fabric of claim 13exhibiting a fabric loss less than 2.0 wt % after 2000 tabor cycles. 15.The composite fabric of claim 14 exhibiting a fabric loss less than 2.0wt % after 2500 tabor cycles.